Prototype
The prototype attempts to simulate a section of a real railroad, often during a certain era. This may require a trip to that section of railroad as well as some research to learn more about that era. If the railroad has a museum, it would also be worthwhile to make a visit.
Freelance
The freelance method makes use of the creativity of the model railroad enthusiast. The designer can re-create a realistic scene from history or invent an entirely original design with unique names for the railroad and individual train cars. Fictional towns can also be built along the tracks.
Garden
The garden railroad works in warmer climates where the display can be left outdoors for extended periods. The track is tailored to the surrounding landscape and makes use of the vegetation and land features to provide a sense of reality. Since the display is built outdoors, there are no limitations on its size.
House
Rather than confining an indoor train to one small space or room, lay a continuous track through several rooms or even the entire house. If feasible, create holes in the walls to serve as tunnels and decorate each room in a theme of a train stop along its journey.
Levels
To maximize a small space, add levels to your display. This can also allow for the creation of bridges and tunnels for more authenticity.